mysql+jdbc,访问blob字段问题，取出时候rs.getBlob方法报错

clc409

我的环境：winxp＋mysql4.1.0alpha-max-nt+tomcat+poolMan(jdbc)

sql:select photo from product where name = '1111'
rs = stmt.executeQuery( sql );
此时执行rs.getMetaData().getColumnTypeName(1)得到：BLOB。
if (rs.next()){
    [color=red]Blob blob = rss.getBlob( column );此句报错[/color]   
    ……
}
错误详细：
java.lang.ClassCastException
        at com.codestudio.sql.PoolManResultSet.getBlob(PoolManResultSet.java:414
)
        at com.xibie.pub.GetPicServlet.service(GetPicServlet.java:81)
        at javax.servlet.http.HttpServlet.service(Unknown Source)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Unkn
own Source)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(Unknown Sour